Update to reveal.js 4.1.2 (#136)

- New tools/ script to manually keep step for updates
- Plugins are all updated
- Template update following latest Pandoc version
- updated README for documentation
- Help page updated 
- See other change in NEWS file
diff --git a/inst/reveal.js-4.1.2/plugin/menu/menu.css b/inst/reveal.js-4.1.2/plugin/menu/menu.css
new file mode 100644
index 0000000..5a300fd
--- /dev/null
+++ b/inst/reveal.js-4.1.2/plugin/menu/menu.css
@@ -0,0 +1,346 @@
+.slide-menu-wrapper {
+  font-family: 'Source Sans Pro', Helvetica, sans-serif;
+}
+
+.slide-menu-wrapper .slide-menu {
+  background-color: #333;
+  z-index: 200;
+  position: fixed;
+  top: 0;
+  width: 300px;
+  height: 100%;
+  /*overflow-y: scroll;*/
+  transition: transform 0.3s;
+  font-size: 16px;
+  font-weight: normal;
+}
+
+.slide-menu-wrapper .slide-menu.slide-menu--wide {
+  width: 500px;
+}
+
+.slide-menu-wrapper .slide-menu.slide-menu--third {
+  width: 33%;
+}
+
+.slide-menu-wrapper .slide-menu.slide-menu--half {
+  width: 50%;
+}
+
+.slide-menu-wrapper .slide-menu.slide-menu--full {
+  width: 95%;
+}
+
+/*
+ * Slides menu
+ */
+
+.slide-menu-wrapper .slide-menu-items {
+  margin: 0;
+  padding: 0;
+  width: 100%;
+  border-bottom: solid 1px #555;
+}
+
+.slide-menu-wrapper .slide-menu-item,
+.slide-menu-wrapper .slide-menu-item-vertical {
+  display: block;
+  text-align: left;
+  padding: 10px 18px;
+  color: #aaa;
+  cursor: pointer;
+}
+
+.slide-menu-wrapper .slide-menu-item-vertical {
+  padding-left: 30px;
+}
+
+.slide-menu-wrapper .slide-menu--wide .slide-menu-item-vertical,
+.slide-menu-wrapper .slide-menu--third .slide-menu-item-vertical,
+.slide-menu-wrapper .slide-menu--half .slide-menu-item-vertical,
+.slide-menu-wrapper .slide-menu--full .slide-menu-item-vertical,
+.slide-menu-wrapper .slide-menu--custom .slide-menu-item-vertical {
+  padding-left: 50px;
+}
+
+.slide-menu-wrapper .slide-menu-item {
+  border-top: solid 1px #555;
+}
+
+.slide-menu-wrapper .active-menu-panel li.selected {
+  background-color: #222;
+  color: white;
+}
+
+.slide-menu-wrapper .active-menu-panel li.active {
+  color: #eee;
+}
+
+.slide-menu-wrapper .slide-menu-item.no-title .slide-menu-item-title,
+.slide-menu-wrapper .slide-menu-item-vertical.no-title .slide-menu-item-title {
+  font-style: italic;
+}
+
+.slide-menu-wrapper .slide-menu-item-number {
+  color: #999;
+  padding-right: 6px;
+}
+
+.slide-menu-wrapper .slide-menu-item i.far,
+.slide-menu-wrapper .slide-menu-item i.fas,
+.slide-menu-wrapper .slide-menu-item-vertical i.far,
+.slide-menu-wrapper .slide-menu-item-vertical i.fas,
+.slide-menu-wrapper .slide-menu-item svg.svg-inline--fa,
+.slide-menu-wrapper .slide-menu-item-vertical svg.svg-inline--fa {
+  padding-right: 12px;
+  display: none;
+}
+
+.slide-menu-wrapper .slide-menu-item.past i.fas.past,
+.slide-menu-wrapper .slide-menu-item-vertical.past i.fas.past,
+.slide-menu-wrapper .slide-menu-item.active i.fas.active,
+.slide-menu-wrapper .slide-menu-item-vertical.active i.fas.active,
+.slide-menu-wrapper .slide-menu-item.future i.far.future,
+.slide-menu-wrapper .slide-menu-item-vertical.future i.far.future,
+.slide-menu-wrapper .slide-menu-item.past svg.svg-inline--fa.past,
+.slide-menu-wrapper .slide-menu-item-vertical.past svg.svg-inline--fa.past,
+.slide-menu-wrapper .slide-menu-item.active svg.svg-inline--fa.active,
+.slide-menu-wrapper .slide-menu-item-vertical.active svg.svg-inline--fa.active,
+.slide-menu-wrapper .slide-menu-item.future svg.svg-inline--fa.future,
+.slide-menu-wrapper .slide-menu-item-vertical.future svg.svg-inline--fa.future {
+  display: inline-block;
+}
+
+.slide-menu-wrapper .slide-menu-item.past i.fas.past,
+.slide-menu-wrapper .slide-menu-item-vertical.past i.fas.past,
+.slide-menu-wrapper .slide-menu-item.future i.far.future,
+.slide-menu-wrapper .slide-menu-item-vertical.future i.far.future,
+.slide-menu-wrapper .slide-menu-item.past svg.svg-inline--fa.past,
+.slide-menu-wrapper .slide-menu-item-vertical.past svg.svg-inline--fa.past,
+.slide-menu-wrapper .slide-menu-item.future svg.svg-inline--fa.future,
+.slide-menu-wrapper .slide-menu-item-vertical.future svg.svg-inline--fa.future {
+  opacity: 0.4;
+}
+
+.slide-menu-wrapper .slide-menu-item.active i.fas.active,
+.slide-menu-wrapper .slide-menu-item-vertical.active i.fas.active,
+.slide-menu-wrapper .slide-menu-item.active svg.svg-inline--fa.active,
+.slide-menu-wrapper .slide-menu-item-vertical.active svg.svg-inline--fa.active {
+  opacity: 0.8;
+}
+
+.slide-menu-wrapper .slide-menu--left {
+  left: 0;
+  -webkit-transform: translateX(-100%);
+  -ms-transform: translateX(-100%);
+  transform: translateX(-100%);
+}
+
+.slide-menu-wrapper .slide-menu--left.active {
+  -webkit-transform: translateX(0);
+  -ms-transform: translateX(0);
+  transform: translateX(0);
+}
+
+.slide-menu-wrapper .slide-menu--right {
+  right: 0;
+  -webkit-transform: translateX(100%);
+  -ms-transform: translateX(100%);
+  transform: translateX(100%);
+}
+
+.slide-menu-wrapper .slide-menu--right.active {
+  -webkit-transform: translateX(0);
+  -ms-transform: translateX(0);
+  transform: translateX(0);
+}
+
+.slide-menu-wrapper {
+  transition: transform 0.3s;
+}
+
+/*
+ * Toolbar
+ */
+.slide-menu-wrapper .slide-menu-toolbar {
+  height: 60px;
+  width: 100%;
+  font-size: 12px;
+  display: table;
+  table-layout: fixed; /* ensures equal width */
+  margin: 0;
+  padding: 0;
+  border-bottom: solid 2px #666;
+}
+
+.slide-menu-wrapper .slide-menu-toolbar > li {
+  display: table-cell;
+  line-height: 150%;
+  text-align: center;
+  vertical-align: middle;
+  cursor: pointer;
+  color: #aaa;
+  border-radius: 3px;
+}
+
+.slide-menu-wrapper .slide-menu-toolbar > li.toolbar-panel-button i,
+.slide-menu-wrapper
+  .slide-menu-toolbar
+  > li.toolbar-panel-button
+  svg.svg-inline--fa {
+  font-size: 1.7em;
+}
+
+.slide-menu-wrapper .slide-menu-toolbar > li.active-toolbar-button {
+  color: white;
+  text-shadow: 0 1px black;
+  text-decoration: underline;
+}
+
+.slide-menu-toolbar > li.toolbar-panel-button:hover {
+  color: white;
+}
+
+.slide-menu-toolbar
+  > li.toolbar-panel-button:hover
+  span.slide-menu-toolbar-label,
+.slide-menu-wrapper
+  .slide-menu-toolbar
+  > li.active-toolbar-button
+  span.slide-menu-toolbar-label {
+  visibility: visible;
+}
+
+/*
+ * Panels
+ */
+.slide-menu-wrapper .slide-menu-panel {
+  position: absolute;
+  width: 100%;
+  visibility: hidden;
+  height: calc(100% - 60px);
+  overflow-x: hidden;
+  overflow-y: auto;
+  color: #aaa;
+}
+
+.slide-menu-wrapper .slide-menu-panel.active-menu-panel {
+  visibility: visible;
+}
+
+.slide-menu-wrapper .slide-menu-panel h1,
+.slide-menu-wrapper .slide-menu-panel h2,
+.slide-menu-wrapper .slide-menu-panel h3,
+.slide-menu-wrapper .slide-menu-panel h4,
+.slide-menu-wrapper .slide-menu-panel h5,
+.slide-menu-wrapper .slide-menu-panel h6 {
+  margin: 20px 0 10px 0;
+  color: #fff;
+  line-height: 1.2;
+  letter-spacing: normal;
+  text-shadow: none;
+}
+
+.slide-menu-wrapper .slide-menu-panel h1 {
+  font-size: 1.6em;
+}
+.slide-menu-wrapper .slide-menu-panel h2 {
+  font-size: 1.4em;
+}
+.slide-menu-wrapper .slide-menu-panel h3 {
+  font-size: 1.3em;
+}
+.slide-menu-wrapper .slide-menu-panel h4 {
+  font-size: 1.1em;
+}
+.slide-menu-wrapper .slide-menu-panel h5 {
+  font-size: 1em;
+}
+.slide-menu-wrapper .slide-menu-panel h6 {
+  font-size: 0.9em;
+}
+
+.slide-menu-wrapper .slide-menu-panel p {
+  margin: 10px 0 5px 0;
+}
+
+.slide-menu-wrapper .slide-menu-panel a {
+  color: #ccc;
+  text-decoration: underline;
+}
+
+.slide-menu-wrapper .slide-menu-panel a:hover {
+  color: white;
+}
+
+.slide-menu-wrapper .slide-menu-item a {
+  text-decoration: none;
+}
+
+.slide-menu-wrapper .slide-menu-custom-panel {
+  width: calc(100% - 20px);
+  padding-left: 10px;
+  padding-right: 10px;
+}
+
+.slide-menu-wrapper .slide-menu-custom-panel .slide-menu-items {
+  width: calc(100% + 20px);
+  margin-left: -10px;
+  margin-right: 10px;
+}
+
+/*
+ * Theme and Transitions buttons
+ */
+
+.slide-menu-wrapper div[data-panel='Themes'] li,
+.slide-menu-wrapper div[data-panel='Transitions'] li {
+  display: block;
+  text-align: left;
+  cursor: pointer;
+  color: #848484;
+}
+
+/*
+ * Menu controls
+ */
+.reveal .slide-menu-button {
+  position: fixed;
+  left: 30px;
+  bottom: 30px;
+  z-index: 30;
+  font-size: 24px;
+}
+
+/*
+ * Menu overlay
+ */
+
+.slide-menu-wrapper .slide-menu-overlay {
+  position: fixed;
+  z-index: 199;
+  top: 0;
+  left: 0;
+  overflow: hidden;
+  width: 0;
+  height: 0;
+  background-color: #000;
+  opacity: 0;
+  transition: opacity 0.3s, width 0s 0.3s, height 0s 0.3s;
+}
+
+.slide-menu-wrapper .slide-menu-overlay.active {
+  width: 100%;
+  height: 100%;
+  opacity: 0.7;
+  transition: opacity 0.3s;
+}
+
+/*
+ * Hide menu for pdf printing
+ */
+body.print-pdf .slide-menu-wrapper .slide-menu,
+body.print-pdf .reveal .slide-menu-button,
+body.print-pdf .slide-menu-wrapper .slide-menu-overlay {
+  display: none;
+}